[单项选择]High Stress May Damage Memory
According to a report issued in May 1998, elderly people who have consistently high blood levels of cortisol don’t score as well on memory tests as their peers with lower levels of the stress hormone. What’s more, high levels of cortisol are also associated with shrinking of the hippocampus, a region of the brain that plays a key role in learning and memory.
The findings suggest that even cortisol levels in the normal, "healthy "range can actually accelerate brain aging.
The study results "now provide substantial evidence that long—term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans, "write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial. Cortisol is a hormone released in response to stress by the adrenal glands, which sit on top of the kidneys.
Over a 5 to 6—year period. Dr. Sonia Lupien and his colleagues measur
A. become larger
B. become smaller
C. be missing
D. be totally damaged